FDR-0019: Implement scoped repo resolution prototype

[friedenberg]

Implements the dodder-side prototype for FDR-0019 (Scoped Repo Resolution), allowing multiple named repositories to coexist per scope under a repos/<name>/ layout while maintaining independent metadata trees.

Summary

This PR introduces a new repo_id.Id type that extends the legacy location-only selector (., /, empty) with an optional name and cwd dot-depth, mirroring madder's blob_store_id grammar. Named repos are addressed via the -repo_id flag and DODDER_REPO_ID environment variable, with each repo maintaining fully isolated metadata (config, index, inventory log, lock) while sharing the content-addressed blob store.

Key Changes

• New internal/bravo/repo_id package: Implements the FDR-0019 grammar parser with Id type supporting:

  • User scope: name or ~name (parse-only alias)
  • Cwd scope: .name or ..name (dot-depth; multi-dot rejected by prototype)
  • System scope: //name or /name (remote-first not implemented)
  • Legacy nameless forms: ., /, empty (auto)
  • Canonical string rendering (single-dot form, no depth)
  • Validation of names (alphanumeric, underscore, hyphen only)

• env_dir.NestUnderRepoName: New function that appends repos/<name>/ to dodder's XDG category directories (data/config/state/cache/runtime), so a named repo's entire metadata tree nests automatically. Blob store XDG is deliberately NOT nested (madder re-derives it, discarding suffixes).

• Integration points: Wired repo_id.Id into three env-construction sites:

  • MakeEnvRepo: Applies nesting for reads
  • OnTheFirstDay (genesis): Applies nesting for initialization
  • MakeLocalWorkingCopyWithOptions: Applies nesting for working copy access
  • All three sites call CheckPrototypeSupported() to reject multi-dot cwd depth

• CLI/config: Updated repo_config_cli.Config.RepoId to use repo_id.Id instead of madder's env_dir.RepoId; updated flag help text to document the full grammar.

• Genesis idempotency: Modified writeBlobStoreConfigIfNecessary to tolerate pre-existing blob store config, allowing multiple named repos in the same scope to share madder's content-addressed blob pool.

• Tests:

  • Unit tests (repo_id/main_test.go): Grammar parsing, canonical round-trip, error cases, depth gate
  • Integration tests (scoped_repos.bats): Two user-scoped named repos isolated, DODDER_REPO_ID addressing, multi-dot rejection

Notable Implementation Details

• Prototype limitations (by design, pending madder env_dir.RepoId change):

  • Empty id resolves to legacy user scope (not FDR's "nearest cwd repo on walk-up, else user default"), preserving backward compatibility
  • Only single-dot cwd depth (.name) resolves; ..name parses but is rejected at resolution
  • /name resolves straight to system scope; remote-first lookup not implemented
  • Blob store remains shared across named repos (full isolation waits on madder change)

• Madder projection: Id.GetMad() converts to madder's legacy env_dir.RepoId for scope routing, so existing MakeDefaultAndInitialize logic continues working unchanged.

• Documentation: Added docs/plans/2026-06-14-fdr-0019-scoped-repos-prototype.md explaining the prototype scope, limitations, and path to the full FDR implementation.

https://claude.ai/code/session_01KnD7hCXXKPqnX1SG4ofL5S